Toothbrush

ABSTRACT

A toothbrush comprises a brush body with a brush head and a carrier platelet attached to the brush head. A plurality of bristle bundles consisting of a thermoplastic material are attached anchor-less to the platelet. The brush head in addition has: bores, recesses or holes which have bristle bundles inserted and affixed with anchors or loops; and/or bores, recesses or holes which have knobs, pegs, pointed bristles or pointed cones inserted therein; and/or knobs, pegs, pointed bristles or pointed cones attached to the brush head.

The present invention relates to a toothbrush.

Several methods of making brushes are known. Conventionally, a brush body is provided with an array of holes corresponding to the desired array of bristles. Bundles or tufts of bristles are then inserted into the holes of the brush body and anchored therein by means of pressed-in small metallic anchors or by means of loops.

In an alternative method of making brushes, which has gained acceptance within just a few years and is referred to as AFT method (Anchor Free Tufting), the tufts of bristles are attached to a carrier platelet without loops or anchors, and the carrier platelet is then installed in or attached to a brush body. The carrier platelet may be connected with the brush body by injection molding or welding. The carrier platelet is provided with holes corresponding to the desired hole pattern. The tufts of bristles are inserted into the holes, with the bristle tufts projecting from a surface of the carrier. The bristles have attachment ends that slightly project on the opposite surface of the carrier. A heated stamp is pressed against the projecting attachment ends of the bristle tufts, the stamp causing the ends of the bristle tufts to be fused together and shaped to form a thickened knob, if desired. The ends of the bristles on the useful side may be pre-rounded or chemically provided with a point in advance. A suitable device for the attachment of tufts of bristles to carrier platelets for making brushes using the AFT method is disclosed in particular in EP 1 136 017 B1.

However, not all types of bristles can be processed using the AFT method. It is not possible to process, e.g., natural bristles or bristles made of or coated with TPE, specially structured bodies such as knobs or pegs, pointed cones made of TPE and the like, since these are not fusible.

The AFT method is also practically not suitable for processing chemically pointed bristles since the points of these bristles are so thin that because of their low inherent stiffness they tend to bend or buckle when they are inserted into the holes of the carrier platelet.

The present invention allows to make use of the advantages of the AFT method while nevertheless allowing to process natural bristles or specially structured bodies such as knobs, pegs or pointed cones as well as pointed bristles.

According to a first approach, the invention provides a toothbrush which comprises a brush body with a brush head and a carrier platelet attached to the brush head. A plurality of bristle bundles consisting of a thermoplastic material are attached anchor-less to the platelet. The brush head in addition has: bores, recesses or holes which have bristle bundles inserted and affixed with anchors or loops; and/or bores, recesses or holes which have knobs, pegs, pointed bristles or pointed cones inserted therein; and/or knobs, pegs, pointed bristles or pointed cones attached to the brush head.

According to a second approach, the invention provides a toothbrush comprising a brush body including a brush head having a plurality of recesses or deepened or raised mounting surfaces which each have one carrier platelet inserted therein or applied thereto and attached thereto, the carrier platelet having bristle bundles made of a thermoplastic material attached thereto without anchor, the bristle bundles of the different carrier platelets jointly constituting an array of bristles.

According to a third approach, the invention provides a toothbrush comprising a brush body including a brush head having at least one recess or a deepened or raised mounting surface having a carrier platelet inserted therein or applied thereto and attached thereto, the carrier platelet having bristle bundles made up of pre-pointed bristles made of a thermoplastic material attached thereto without anchor, which, following their attachment, having been given a completed pointed shape by means of a post-treatment.

Further features and advantages of the invention will be apparent from the description below and from the accompanying drawings to which reference is made and in which:

FIG. 1 shows a perspective view of a head of a toothbrush in accordance with a first embodiment;

FIG. 2 shows the head of a brush body with a bristle carrier platelet to be attached thereto,

FIG. 3 shows a perspective view of a head of a toothbrush in accordance with a second embodiment;

FIGS. 4 a and 4 b each show one single chemically or mechanically pointed bristle in the AFT method; and

FIGS. 5 a and 5 b each show one single chemically or mechanically pre-pointed bristle in the AFT method.

In the first embodiment of a toothbrush, shown in FIGS. 1 and 2, the array of bristles of the toothbrush consists of different types of bristles. The head of the brush body generally denoted by 10 has a recess 12 in which a carrier platelet 14 is inserted, with bristles attached to it. The bristles are bundled to form oblong groups 16 a, 16 b, 16 c . . . These bristles consist of a thermoplastic material and are attached to the carrier platelet 14 using the AFT method described at the outset. In addition, the head of the brush body 10 includes two groups of holes 18 a, 18 b for bundles, which have bristle bundles 20 a, 20 b inserted therein and attached by means of anchors or loops in a conventional manner. The bristle bundles 20 a, 20 b consist of a material that can not be processed using the AFT method because it is not fusible. This is the case with natural bristles, for example. Chemically or mechanically pointed bristles are another example: owing to the fineness of their pointed ends on the useful side, these bristles have such a low inherent stiffness that they would tend to bend or deflect transversely to the longitudinal direction of the elongate bristle body when they are inserted into holes of a carrier platelet.

Applying the same principle, structured bodies, in particular made of an elastomer material, in the form of knobs, pegs or pointed cones may be attached in holes or recesses of the brush body 10. In this way, it is possible to make use of the advantages of the AFT method while at the same time arranging natural bristles or structured bodies having any desired shape in the space for the bristles, which do not lend themselves to processing using the AFT method.

In the embodiment shown in FIG. 3, three carrier platelets, each with one group 32, 34, 36 of bristle bundles attached thereto, are arranged on the head of a brush body 30. The groups 32, 34, 36 of bristle bundles together constitute the array of bristles of the toothbrush. The groups 34, 36 are of an approximately mirror-symmetrical shape, while the group 32 is more or less complementary to the groups 34, 36. In this embodiment, the bristle bundles are attached to the respective carrier platelets using the AFT method. Each of the carrier platelets is inserted into a corresponding recess in the head of the brush body 30 and attached therein. As an alternative, the head of the brush body is provided with deepened or raised mounting surfaces, with carrier platelets being applied to or placed on and attached to the mounting surfaces.

FIGS. 4 a and 4 b illustrate the problems involved in the AFT method in the case of chemically or mechanically pointed bristles. FIG. 4 a shows a single bristle, pointed in this manner, from a bundle of bristles. The bristle has an elongate bristle body. When the bristle is axially inserted into a carrier platelet, its tip will bend due to its lack of inherent stiffness (FIG. 4 b), which is the reason why the bristle bundles are anchored in bundle holes in a conventional fashion. It has now been found, however, that bristles made of a fusible material which are only pre-pointed chemically or mechanically, may be attached to a carrier platelet using the AFT method. In that case, the bristles have been subjected to a mechanical or chemical pre-treatment so as to give them a pointed shape at the end on the useful side thereof. This pointed shape is not so pronounced as to prevent the bristles from being processed using the AFT method due to their insufficient inherent stiffness. FIG. 5 a illustrates the axial insertion of an only pre-pointed bristle and indicates the fusion with the carrier platelet. FIG. 5 b indicates a post-treatment, e.g. by means of grinding, to complete the process of pointing the bristle ends following the fusion. In this way, it is possible to use the AFT method to produce a complete toothbrush whose array of bristles consists in full or in part of pre-pointed and post-treated bristles. 

1. A toothbrush comprising a brush body with a brush head and at least one carrier platelet attached to said brush head, a plurality of bristle bundles consisting of a thermoplastic material being attached anchor-less to said platelet, the brush head in addition having at least one of bores, recesses or holes which have bristle bundles inserted and affixed with anchors or loops, bores, recesses or holes which have knobs, pegs, pointed bristles or pointed cones inserted therein, and knobs, pegs, pointed bristles or pointed cones attached to said brush head.
 2. The toothbrush according to claim 1, in which the bristle bundles, knobs, pegs or pointed cones consist of a material that is not fusible.
 3. The toothbrush according to claim 1, in which the cones or bristles each have an elongate body with such a low inherent stiffness that the pointed end prevents an introduction into a hole by bending or yielding transversely to the elongate body.
 4. The toothbrush according to claim 1, in which the bores or holes have bundles of natural bristles inserted therein.
 5. The toothbrush according to claim 1, in which the bores or holes have knobs, pegs or pointed cones made of an elastomer material inserted therein.
 6. The toothbrush according to claim 1, in which the knobs, pegs or pointed cones are molded from an elastomer material, the brush body is molded from a relatively hard plastics material and the brush body is molded with the knobs, pegs or pointed cones in a two-component injection molding process.
 7. The toothbrush according to claim 1, in which the carrier platelet has bristle bundles consisting of pre-pointed bristles attached to the platelet.
 8. The toothbrush according to claim 7, wherein the pre-pointed bristles after attachment to the platelet are given a completed pointed shape by means of a post-treatment.
 9. A toothbrush comprising a brush body including a brush head having a plurality of recesses or deepened or raised mounting surfaces which each have one carrier platelet inserted therein or applied thereto and attached thereto, the carrier platelet having bristle bundles made of a thermoplastic material anchor-less attached thereto, the bristle bundles of different carrier platelets jointly constituting an array of bristles.
 10. The toothbrush according to claim 9, in which at least two of the carrier platelets have different shapes.
 11. A toothbrush comprising a brush body including a brush head having at least one recess or a deepened or raised mounting surface having a carrier platelet inserted therein or applied thereto and attached thereto, the carrier platelet having bristle bundles made up of pre-pointed bristles made of a thermoplastic material anchor-less attached thereto, the bristles, following their attachment, being given a completed pointed shape by means of a post-treatment.
 12. A method of making a toothbrush comprising a brush body including a brush head having at least one recess or a deepened or raised mounting surface having a carrier platelet inserted therein or applied thereto and attached thereto, comprising the steps of: a) anchor-less attaching to the carrier platelet bristle bundles made up of prepointed bristles made of a thermoplastic material; and b) following attachment, post-treating the pre-pointed bristles to give them a completed pointed shape.
 13. A method according to claim 12, wherein the post-treatment is grinding.
 14. A method according to claim 12, wherein the pre-pointed bristles are not so pointed that they bend, due to insufficient inherent stiffness, when inserted into a carrier platelet.
 15. A method according to claim 12, wherein the pre-pointed bristles are pre-pointed by chemical or mechanical pre-treatment. 